1. Field of the Invention
This invention relates to apparatus for moving an exposed film unit from a film cassette and into engagement with a pair of pressure-applying rollers.
2. Description of the Prior Art
Photographic apparatus of the type having manually operative film advancing means for moving an exposed film unit into engagement with a pair of elongate rollers for subsequent processing are relatively well known. For example, U.S. Pat. No. 2,873,658 shows a camera having a manually actuatable film advancing member mounted for movement between first and second positions for moving an exposed film unit into the bite of a pair of processing rollers. A spring, connected to the film advancing member, is tensioned during the movement of the latter toward the second position and provides a force for returning the film advancing member to the first position. Obviously, if the spring is to perform its function, it must be strong enough to overcome the frictional force created between the film advancing member and its mounting structure during such return movement. Accordingly, it can be seen that if this frictional force could be substantially reduced, the spring could be replaced by a less powerful and therefore less inexpensive one.
U.S. Pat. No. 3,826,655 presents a situation similar to that of the U.S. Pat. No. 2,873,658 patent supra except here the film advancing member is motor driven in a manner which cants the film engaging portion of the member into alignment with a diverter bar attached to the leading edge of a film unit. However, there does not appear to be any reduction in the frictional force between the film advancing member and its mounting structure prior to its return to the first position.
U.S. Pat. No. 4,068,244 shows a camera having a manually actuatable film advancing member wherein the frictional force between it and a ratchet structure is substantially reduced prior to being returned to its original or first position. However, the ratchet structure is not a part of the mounting structure for the film advancing member and there does not appear to be any substantial reduction in the frictional forces acting therebetween prior to moving the film advancing member back to the first position.